Biomedical Engineering Reference
In-Depth Information
Restorative dental materials include synthetic components, acid
base cements, amalgam, resin-
based composites, noble and base metals, ceramics, and denture polymers
[3,4]
. The ideal
restorative material should be biocompatible, bond permanently to tooth structure or bone, match
the natural appearance of tooth structure and other visible tissues, and be capable of initiating tissue
repair or regeneration of missing or damaged tissues
[4]
. The moisture environment of oral cavity
poses many challenges to restorative materials; in addition, they should withstand the effect of
masticatory forces, enzymatic attacks, variation of pH, and temperature. Bite forces can vary from
100 to 500 N depending on the position in the mouth and of the individual
[5]
. Microleakage
between the tooth and restoration can lead to colonization by bacteria and development of second-
ary caries, and subsequently, failure of restoration
[6]
.
5.2
Smart dental materials
Within the field of restorative dentistry, the incredible advances in dental materials research have
led to the current availability of esthetic adhesive restorations, conducting the profession into the
“post-amalgam era”
[7]
. It has been clearly established that this new biomimetic approach to restor-
ative dentistry is possible through the use of composite resins/porcelains and the generation of a
hard tissue bond. The development of nanomaterials has moved nanotechnology from its theoretical
foundations into mainstream practice
[8]
. Clinicians have been using certain criteria to select dental
materials, e.g., (i) analysis of the problem, (ii) consideration of requirement, and (iii) available
materials and their properties
[9]
.
Materials demonstrating an optimum combination of smart interactions and longevity are likely
to have some combination of stable resin matrix combined with a coexistent salt matrix or discreet
phase. The rapid developments in nanotechnology propose that such features can be manufactured
into compounds using building blocks at an atomic or molecular level. Friend
[10]
reported that
The development of true smart materials at the atomic scale is still some way off, although the
enabling technologies are under development. These require novel aspects of nanotechnology (tech-
nologies associated with materials and processes at the nano-meter scale, 10
2
9
m) and the newly
developing science of shape chemistry.
5.3
Nanotechnology and dentistry
Nanotechnology has revolutionized the field of science and technology. It is the production of func-
tional materials and structures in the range of 0.1
100 nm by various physical and chemical
methods and also known as molecular nanotechnology or molecular engineering. It has led to the
development of new restorative materials containing nanoparticles. The interest in using nanomater-
ials stems from the idea that they can be used to manipulate the structure and properties of the
materials
[11]
. Nanotechnology is of great interest in biomaterials engineering and in the develop-
ment of dental materials
[2]
. The particle size of dental restorative materials is so dissimilar to the
tooth structure such as hydroxyapatite (HA) crystal, dentinal tubules and enamel rod that there is a
potential for compromises in adhesion between the macroscopic (40
0.7 nm) restorative material
